Differential water-heater.



A. A. GARDWELL. DIFFERENTIAL WATER HEATER. APPLIUATION FILED MAR.15, 1911.

Patented July 11, 1911.

rr an ADDISON A. CARDW-ELL, OF RYE, NEW YORK, ASSIGNOR T JOHN `O. DAVIS, OE

HARTFORD, CONNECTICUT.

Specification of Letters Patent.

Application ined March 15, 1911. serial No. 614,596.

vTo all whom it may cof/warn;`

Be it known thatI, ADDISON-A. CARM-'191111, of Rye, in the county of Westchester and State of New York, have invented certain new and useful Improvements in Differential Tater-Heaters', of which the following is a specification.

The present invention relates to means for heating water by means of an already heated fluid which is circulated through a coil of pipes in a tank containing the water to be heated. The water thus heated Amay be used for any purpose, but this invention is principally applicable for heating water whichl is circulated through radiators and pipes of a building for warming the rooms thereof.

The main object of the invention is to permit of a4 regulated degree and rate of heating of thewa'ter by causing the effect-ive length and .heating surface of the coil, through which the circulating fluid flows, to be increased or diminished at will. The heating `fluid, which is employed to impart heat to the water, is ordinarily steam, and

a second object of the invention is to enable the water of condensation to be separated from the steam at different stages of its course through the heatingv coil, so that only live steam or the water condensed in the coil from the steam comes into thermal relation y with the water to be'heated, whereby the heating effect and efiiciency of the coil is increased. l

The manner in which I accomplish the objects above vset forth is described in detail y in the'A following specification and illustrated in the drawings forming a part thereof. In the latter,-Figure 1 represents a longitudinal section of a heater embodying my invention, Fig. 2 is a similar view showing a dif-V ferent construction of some of the parts but all embodying the same principles, and Fig.

Sis a frontend elevation of the`hea'ter shown` the tank. The plate 6 has a flange 7 which is bolted or otherwise secured to the plate or head 5 and incloses the space between the two plates; Extending across between the plates and from side to side of thetank are partitions 8, 9 and 10, dividing the space between the plates into chambers 11, 12, 13 and 14. In this embodiment of the invention, three partitions and four chambers are shown, but the exact number is not material -to the invention, since the same principles may be embodied in an apparatus having only three chambers and also in one having more than four chambers, as well as in t-he particular number herein illust-rated. Se cured in the plate 5 are the ends of return tubes 15 which have their inlets. opening into the chamber 11 and their outlets opening into the chamber 12. 'That is their inlet andoutlet ends are respectively on opposite sides of the partition Other 'return tubes 16 have their ends fastened in the plate 5 respectively above and below the partition 9 so as to receive fluid from the chamber 12 and discharge it into the chamber 13, while tank, as shown in Fig. 3, the tubes of eachv .set being in parallel while the tubes of the several sets are in series and communicate with each other through the chambers12 and 13. In a heater having more or' fewer chambers as above suggested, a correspond- -ingly less or'gr'eater number of lsets,` of re-v turn tubes' is provided, but the principle inV any case is the same provided there are at least two sets of such tubes.- The heating `fluid, which ordinarily is steam, is conducted Patented July 11, m11.,

from a' boiler to the chamber 11 through a pipe 18, and thence flows through the vtubes 15- to the chamber 12, givingv its heat to the water vin the tank. In the outer wall or' jplate '6 are outlets 19, 20 and`21 respectively lwhich' `register with openings in a valve chamber '22: 'The latter -in form is an .open

boX andhas 'valves 23, 424:V and 25 opposite, th'e several 'holesand' adapted 'to close the \same lby seating' against 'valve seats secured 'in the inner' wall of the' valve box and surrounding tlie holes `)as clearly shown in Fig. 1. TheseV valves are lcontrolled by hand wheels mounted on 4valve stems which pass through the outer wall of the valve case and are packed by stuffing boxes. From the lower end of the valve case, a discharge pipe 26 conducts the water of condensation and exhaust steam to a steam trap and back to the boiler. No circulation of the steam through the return tubes is permitted except when at least one of the valves 23, 24 or 25 is opened. Assuming that the valve 25, is opened and the other valves closed, the circulation of steam is from the pipe 18 and chamber l1 through the return tube 15 to the chamber 12, thence through tubes 16 to chamber 13, thence through tubes 17 to chamber 14, and finally through the outlet 21 to the return pipe 26. The severalsets of return tubes thus constitute a continuous coil through which the steam is passed and of which the entire length and heating sur-- face are utilized to transfer heat from the steam to the water. The full extent of the heating coil is thus used when it is desired to heat the Water to and maintain it at the highest degree possible, as in heating a buildingin extremely col'd weather. When a more moderate degree of heating is desired, the valve 25 is closed and the valve 24 opened, thus preventing circulation of the steam through the lowest'tubes 17 and which immediately -ll with water of condensation, allowing that discharged from the intermediate tubes 16 to pass directly to the outlet 26. .When still less heat is required, both the valves 25 and 24 are closed and valve 23 is opened, allowing the exhaust steam and water of condensation to pass away as soon as the steam has passed through the upper set of tubes, the lower two sets being full of condensation and outv of commission. In this way, a regulation of t-he amount of heat imparted to the watei` is made, andthe Water,

,Y which circulates through the heating system of the building, may be kept at a substan- .tially uniform temperature in mild, moderate and severe weather. v

When steam is used as the heating agent, a certain proportion of it will be condensed in the coils in consequence of giving up its The heating efficiency is greatly diminished if that water, which is condensed in the first coils or tubes or in the supply pipe 18, is carried with the steam through all the tubes, because the latent heat/is absent. For the purpose of allowing only uncondensed steam to pass through the4 coil in all stages, I have provided a means for separating the water of condensation or of entrainment from the steam at each stage. For this purpose, I provide holes or openings 27, 28 and 29 in the partitions 8, 9, and 10 respectively.

atever water is brought with they steam into the chamber 11 falls through the open-- ing 27 into the chamber below while the steam passes through the tubes 15. Likepath of least resistance.

wise the water which falls through the holes 27, together with the water produced by condensation in the tubes 15, passes through the holes 28 in the partition 9 to the chamber 13, and so on, until all the Water condensed in the entire heater passes through the outlet 26. When any of the lower chambers and tubes are shut off by closing of the outlet 21 or 20, the water collecting in the chambers llls up the lower chambers and tubes to the level of the outlet 20 or 19, whichever may be open. Since each of the tubes is held at both ends in the same plate or tube sheet 5,

`whatever distortion of the tubes takes place through heating and cooling produces no harm, because the entire length of the tubes between their ends isfree. Thus the ,differences of temperature which result from closing some of the tubes and allowing them to fill with Water while-the other tubes contain live steam, does not distort the tube sheets or loosen the tubes and cause leakage.

As appears from Fig. 3, the parallel tubes of the several series are staggered so thatI the steam which issues from the outlet of any one tube does not all pass into the tube next below but is divided among two or more of the tubes, and a diiiusion of the steam through the several tubes in the successive series is accomplished. i

In this invention, yI consider that thel artitions dividing the several chambers rom one another are a necessity in order to compel the steam to follow a sinuous course through the several series of tubes. Direct passage of the steam to the discharge through the holes in the several partitions is prevented by the water of condensation which collects in all the chambers, and by the fact that these holes are so proportioned as ordinarily to retard the flow of water to such an extent as to obstruct the steam and to cause the steam to'follow the tubes as the In case the heating agent should be another fluid than steam and not liable to condensation in the tubes, the holes 27,28 and 29 could be omitted or plugged. l

In Fig. 2 is shown a working out of the invention somewhat different from that -shown in Fig. 1 but embodying the same principles.

In this form of the invention, the tubes, chambers and partitions are `the same as above described, and are designated by the same numerals. Instead of the common valve chamber containing all the valves, however, I have provided separate outlet pipes leading from each chamber to the discharge pipe 26, these several pipes being designated by 30,v 31 and 32 respectively,

and each having its own valve; The oper' ation however is identical with that already described.

To avoid pocketing of air in the several chambers, I propose to employ air vents as '997,749 all;

indicated at 33, 34, 35 and l36 in Figs. 2`

and 3.

I claim I l. A heater comprising a tank, a head at one end of the tank, an outer wall adjacent to said head and partitions between the head andv wall dividing the intermediate space into a series of separate chambers, 'a series of return tubes one above another, the uppermost of such tubes having its ends opening into the'first and second chambers, and the next lower tube having its ends opening to the second and third chambers, mea-ns for admitting steam to the uppermost chamber, and separate outlets, adapted to be independently closed, leading from the lower chambers.

2. A .water heater, comprising a tank, a sei-ies of tubes arranged so that a heating fluid is caused to ilow through them suceessivel y, whereby they form in effect a heating coil, means for admitting the heating luid to the first tube of the series, and means for imlelumdently drawing ofi' Huid from different parts of the coil, whereby the extent ot' 'heating surface may be varied.

3. A water heater, comprising a tank, a

series of tubes arranged so that a heating [luid is mused to iow through them successvel y, whereby they form in effect a heating coil, means for admitting the heating fluid to the first tube of the series, a plurality of outlets for the exhausted fluid at different points in the coil, and means controlling said outlets operable to permit escape of the Iluid from any one of the outlets and prevent esca e from the others.

4. A heatlng coil, comprising a series of' return tubes one above another, a late or tube sheet into which both ends -of t e tubes are secured, a second plate beside said tube sheet, and partitions extending across the space between said plates and located between the inlet and outlet endsof the respective tubes, forming se arate chambers into whlch the outlet and 1n ets of successive' tubes open whereby the heating fluid is sive tubes and chahnbers, means for admitting steam to the uppermost chamber,- outlets from the lower chambers, and independent valves for each of said outlets. l

5. A heating coil, comprising a series o return tubes one above another, a plate or tube sheet into which both ends of the tubes are secured, a second plate beside said tube sheet, and partitions extending across the space between said plates and located between the inlet and loutlet ends of the respective tubes, forming separate chambers into which the outlet and inlets of successivel tubes open whereby the` heatln luid is caused to pass in order through t e successive tubes and chambers, means for ad-v mitting steam to the uppermost chamber, and provisions for drawmg water from the upper chambers so that only steam may enter the tubes.

G. A water heater, comprising a tank, a series of return tubes, a series of chambers outside of the tank through which the return ends and the admission ends of successive tubes are coupled, whereby steam admitted to the upermostchamber and tube is compelled to ow in order through the tubes, means for draining water from the upper chamber to the one below, and an outlet from the lower chamber.

7. A water heater, comprising a tank, a series lof return tubes, a series of chambers outside of the tank through which the return ends and the admission ends of successive tubes are coupled, whereby steam admltted to the uppermost chamber and tube 1s compelled to low in order through the tubes,

provisions in the chambers for preventing water delivered from any tube from passing into the next tube of the series, andan outlet for both water and steam from the last chamber of thel series.

In testimony whereof I have afxed my signature, in presence of two witnesses.

ADDISON A. CARDWELL. Witnesses:

WM. H. GEE, A. H. OARDWELL. 

